Meat is one of the primary sources of food, obtained by butchering the corpses of animals (and possibly humans). It can be used alone to produce simple meals, or combined with other ingredients to produce fine, lavish meals, pemmican and kibble. As a raw food item, colonists dislike eating uncooked meat.
Each stack of meat is labeled to identify the species it came from. In most cases, the properties of meat do not differ by species and the stats on this page apply to all of them. There are two exceptions, however.
Colonists consider insect meat disgusting, and will suffer the "Ate cooked insect meat" bad thought (-3 mood) when eating meals made with it. Cooking it into a fine meal (+5 mood) offsets this penalty for a total of +2 mood, making cooking insect meat worthwhile if a colony's food supplies are low. By default, cooks will not cook with insect meat, but you can make them do so by allowing insect meat in cooking bills. Eating uncooked insect meat is worse, but not nearly as bad as ...
Much like insect meat, colonists are generally opposed to consuming human flesh, so much so that your cooks will not butcher human corpses by default. Unless your butcher enjoys the "Psychopath," "Bloodlust," or "Cannibal" traits, butchering humanlike corpses generates a long-lasting -6 mood bad thought and even other colonists who didn't do the butchering suffer a mood debuff.
Only colonists with the Cannibal trait will appreciate the meal, while all others will get hammered with a -20 mood bad thought. Consider all other options before resorting to cannibalism to keep your colony up and running. To prevent the additional Raw Cannibalism debuff, always cook it first. You might choose to suffer the additional penalty to put it through a nutrient paste dispenser until you can obtain more food.